The present invention generally relates to pallets and more particularly to an improved paperboard pallet made using novel paperboard runners.
Pallets have been made for many years completely of wood and such pallets ordinarily are re-used a number of times. Thereafter, however, the wood pallets must be disposed of in an acceptable manner. This disposal problem is magnified when large assembly plants, e.g. automobile assembly plants, are considered since thousands of wood pallets must be disposed of in an acceptable manner.
The art, then, has turned to disposable pallets made of corrugated paper. Such paperboard pallets, however, have not been found to be generally satisfactory, being deficient in areas including lateral stability and cost. Moreover, such paperboard pallets must be capable of being moved by conventional forklift trucks.
Such prior paperboard pallets can be exemplified by U.S. Pat. No. 2,997,266 which proposes a pallet structure wherein U-shaped wood block members provide structural rigidity to each of the paperboard beams. U.S. Pat. No. 3,000,603, calls for tabs to be inserted into rectangular openings in the beams and engage slots in a central vertical wall. U.S. Pat. No. 3,601,067 utilizes reinforced legs and collars for the pallet structure. U.S. Pat. No. 3,659,534 provides for S-shaped folds at the end of each sheet in order to provide structure for the pallet. U.S. Pat. No. 4,100,859 utilizes "egg-carton" type inserts for providing rigidity to the forklift pallet. U.S. Pat. No. 4,303,020 utilizes wood stiffening elements in the paperboard pallet while U.S. Pat. No. 4,563,377 provides a folded beam structure. U.S. Pat. No. 4,714,026 provides blocks for reinforcing the beams that support the pallet. U.S. Pat. No. 4,802,421 provides circular cross elements for stiffening of the lateral beams. U.S. Pat. No. 4,936,229 provides for a grid of slotted vertical members for providing rigidity to the pallet. U.S. Pat. No. 5,001,991 provides a cross beam structure of folded cardboard for construction of a pallet.
Despite the art on paperboard pallets, load bearing capability, lateral deflection strength, and economy of cost are a combination of factors that have eluded the art. Moreover, a truly collapsible paperboard pallet has yet to be proposed.